Protons do not like to remain close each other for very long. But if you have got the right number balanced neatly among enough neutrons, they only might build an atom that will not crumble apart in the blink of an eye fixed.
Theorists had suggested 114 might be one such magic number of protons, but a recent experiment conducted at GSI Helmholtz Centre for Heavy Ion Research in Germany now makes that incredibly un-likely.
In 1998, Russian experimenters finally succeeded in building an element with 114 protons in its nucleus. It had been later named flerovium after its birthplace, Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research.
Creating mammoth-sized atoms is by-no means easy, achieved only by starting with heavy weight elements like plutonium and pelting them with slightly smaller ones like calcium, until something sticks.
By sticks, we mean ‘pauses long enough to technically pass for an atom’, which for mountain-sized nuclei is rarely more than a fraction of a second. For instance, at 112 protons in size, the transuranic element of copernicium has little-chance of lasting more than 280 microseconds.
Atomic nucleons hold onto each other as an effect of the strong interaction shared between the trios of sub-atomic quarks that make them-up.
At the same–time, repulsive nature of positive charges in protons push-them apart, meaning, the entire structure teeters on the brink of collapse, should they come too-close together. This is often why we see some combinations of nucleons or isotopes, more than others.
Once an atom gets to a particular size, a slew of other factors to do with energy & mass also weigh in, making it harder & harder for the atom to-hold itself together, to not mention more than for physicists to-predict its characteristics.
Yet physicists are confident that there’re islands of stability in the upper-reaches of the periodic table, where arrangements of protons can form patterns & shapes that allow them to hold on-to life a little longer than neighboring elements.
Nihonium or element 113, has an isotope with a half-life of about 20 seconds, for instance.
When signs of flerovium first sifted-out of a debris of plutonium & calcium more than 20 years ago, however, it seemed like a real keeper. The signature in the data suggested atoms remaining stable for as long as 30 seconds before spitting-out an alpha particle & crumbling briefly into copernicium.
The excitement was short-lived. In 2009, the Berkeley scientists managed to re-create 2 different isotopes of the element. One lasted a tenth-of-a-second. The second hung around slightly longer, falling apart after half-a-second.
The odds were not looking good for element 114, but physicists are not the kinds to leave well-enough alone. Therefore, the University of Mainz went big, using upgraded detectors to study tons of possible flerovium decay events.
In end, two confirmed as bonafide isotopes. One resulted in an isotope of copernicium that was seen breaking-down in a way that had not been previously observed.
In that event, flerovium decay chain occurred inside 2.4 seconds, in a shedding of alpha-particles. The second isotope was gone in just 52.6 milliseconds. Importantly, efficient way each of the 2 isotopes decayed made it clear that 114 was not stable in the least.
As exciting as a stable flerovium may have been, the novel-findings of an excited state of copernicium provides solid ground for exploring islands of stability higher-up the periodic table, giving theorists vital-information for modelling this phenomenon further.
“The existence of the state provides yet one more anchor point for nuclear theory, because it seems to need an understanding of both shape co-existence & shape transitions for the heaviest elements,” the researchers write in their report.
While we can now all, but rule-out 114 as one of the magic numbers of the periodic table, there are more-giants left to slay.
Physicists are yet to create the hypothetical element tentatively called unbinilium or element 120. Crafting one among those monsters would take some powerful technology & advanced knowledge of nuclear physics.
This research had been published in Physical Review Letters.